We have investigated neurotransmitter metabolites and glucose metabolism in incarcerated violent offenders, arsonists, and healthy volunteers. We have found that low cerebrospinal fluid (CSF), 5-hydroxyindoleacetic acid (5-HIAA) concentrations, and hypoglycemia during oral glucose tolerance tests are associated with each other and impulsive violent acts and fire setting. To elucidate the pathophysiology of the reactive hypoglycemia, englycemic insulin clamp studies with indirect calorimetry have been performed on more than 40 offenders and healthy volunteers. The data have not been analyzed, because initial power calculations indicated that a larger sample size is necessary. Sample collection for the molecular genetic family study on alcoholic violent offenders has been completed. The clinical data have been blind rated for psychiatric diagnoses and all biochemical and physiological data have been entered in the computers and double checked for errors. Molecular genetic analyses in the Laboratory of Neurogenetics are underway. Thirteen hundred DNA samples, which represent a random sample of Finns, and which are without identifiers, were received from Dr. Leena Peltoven in the National Public Health Institute in Helsinki. Together with our own control sample which consists of 300 volunteers, these samples will be used to establish the true allelic frequencies of rare polymorphisms among the Finnish population.